1. Field of the Invention
The present invention relates to an optical scanning device that irradiates a photoconductor with light beams to form an electrostatic latent image thereon, and an image forming apparatus using the optical scanning device.
2. Description of the Related Art
There have been image forming apparatuses such as a printer and a copying machine, which include an optical scanning device. The optical scanning device includes a light source that emits light beams (for example, laser beams) corresponding to image data, and a deflector that deflects and scans the light beams, thereby irradiating a photoconductor with linear light beams. In the image forming apparatus, for example, the deflector reflects light beams to irradiate the photoconductor and forms an electrostatic latent image on the photoconductor. Then, toner is supplied to the photoconductor to develop the electrostatic latent image into a toner image. A transfer device transfers the toner image formed on the photoconductor to a recording medium. After that, a fixing unit fixes the toner image on the recording medium, and the recording medium is ejected from the image forming apparatus.
Recently, an optical scanning system is applied to image forming apparatuses that include a plurality of photoconductors. In the optical scanning system, light beams emitted from a plurality of light sources are separated almost symmetrically and deflection-scanned. This system requires a very complicated configuration where many optical systems are arranged in a single housing.
In such an optical scanning device, it is essential to prevent unnecessary reflected light and scattered light (flare light) from reaching the surface of the photoconductor. In the aforementioned optical scanning system, flare light reflected by an optical system often passes through another optical system on the opposite side, and reaches the surface of the photoconductor. It is particularly important to remove the flare light passing near a deflector. Japanese Patent Application Laid-Open Nos. 2002-196269 and 2003-202512 disclose a conventional image forming apparatus that includes a light shielding member.
The conventional image forming apparatus is capable of shielding light; however, noise generated between an apex of a polygon rotor of the deflector and the light shielding member, and a windage loss during rotation of the deflector increase due to the light shielding member arranged near the deflector.